Factual error: Firearm issues abound throughout the film. The British detectives (who all seem to be armed, rather than a low proportion of AFO (Authorised Firearms Officers) as in real life) are shown carrying Beretta pistols, even though the Metropolitan Police issue the Glock 17. The SFO (Specialist Firearms Operations) officers are shown carrying MP5 submachineguns, which is accurate, but fitted with cheap toy-shop lasers. Weapons handling is poor throughout, with chickenwing syndrome particularly prevalent. Weapons carriage also appears geared to look "cool" rather than realistic; shoulder holsters - which practically everyone wears in this film - are rarely used for concealed carry in reality.
Continuity mistake: In the 2nd meeting between Emily and James, she brings him supplies. Emily is seen twisting at the cap on the bottled water before handing it to James. However, when she hands it to him, the cap is visibly still on the bottle. James is then seen removing the cap himself. He sets the cap on the table, takes a drink, then puts the bottle on the table. The next shot shows Emily with her hands in her lap then reaching for the bottle and putting the cap back on as if the cap was already in her hand. She never removed he cap. The cap would still be on the table where James put it. There is no way she could have retrieved that cap off the table without coming into camera view.